Process of making a thioindigo dye.



, UNITED STATES PATEN T OFFICE.

EDTIARD M'U'NCI'I, 0F LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNQR TO BADISGHE ANILIN & SODA FABRIK, MANY, A. CORPORATION OF GERMANY.

OF LUDWIGSHAFEN-ON-THE-RHINE, GER- PROCESS OF MAKING A THIOINDIGO DYE.

No Drawing. Application filed September To all whom it may concern:

Be it known that I, EDUARD Mt'iNcH, doctor of philosophy and chemist, a subject of the Grand Duke of Baden, residing at Ludwigshafen-on-the-Rhine, Germany, have in- ,vented new and useful Improvements in the Production of Coloring-Matter Containing Sulfur; of which the following is a specification.

In the specification of application for Letters Patent Serial No. 451,2 I have described the production of acetylene bisthiosalieylic acid compounds by acting with symmetrical dihalogenethylene on a thiosalicylic acidcompound. I have discovered that these acetylene-bis-thiosalicylic acid compounds on treatment with acid condone-- ing agents, such for instance as ordinary sulfuric acid, fuming sulfuric acid, chlorsulfonic acid, 'phosphoric anhydrid. and acetic anhydrid mixed with zinc chlorid or sulfuric acid, give rise to coloring matters of the thioii'idigo group directly with-. out any intermediate formation of the leuco compounds. If desired, a diluting agent, or

a flux, may be present during the reaction.

When concentrated sulfuric acid, or'other reagent which can sulfonate, is used as the condensing agent, the coloring matters can be obtained as such, or as snlfoacids, according to whether the reaction is allowed to proceed moderately, or energetically.

The following examples will serve to illustrate further the nature of my invention andhow it can be carried into practical etfe et, but the invention is not confined to these examples. The parts are by weight.

Example 1,: Introduce thirty parts of acetylene-bis-thiosalicylic acid rapidly into (ii an olive-green solution is obtained.

Specification of Letters Patent. t te F b 15 191() 1, 1908. Serial No. 451,251.

acetylene bis para -brom thiosalicylic acid into two hundred parts of fuming sulfuric acid (containing fifteen er cent. free S0,) at from thirty-five, to fty, degrees centigrade, then stir for a few minutes longer at from forty, to fifty, degrees eentlgrade, and pour the olive-green mixture into ice and water. The coloring matter which separates out can be purified by extraction with dilute caustic soda. It dyes cotton blucred.

trichlorbenz ene to about two hundred degrees centigrade and introduce, whlle well stirring and alternately in smallportlons at Example 3: Heat six hundred parts of a time, ten parts of acetylene-bis-thiosali- I cylie acid and twenty parts of phosphorus pentoxid. After about fifteen minutes, filter the red-violet solution and extract the residue with three hundred parts of boiling trichlorbenzene. Add the filtrates together and allow them to cool, whereupon the col- I oring matter separates out in the form of glittering needles. Filter it off and wash it with 'a little ether. Example 4: Introduce thirtyparts of temperature, into two hundred parts of acetylene-bis-thiosalicylic acid,- at ordinaryfuming sulfuric acid (containing twenty- 7 three per cent. free SO stir for a few hours at from forty, to fifty, degrees centigradeand then pour the mixture into ice and-water. On adding common salt tothe solution, the coloring matter is obtained in the form of its snlfonic acid. It dyes ,wool

from an acid bath bluish red.

Now what I claim is:

1;. The process of producing coloring matter of the thioindigo group by treating an acetylene bis thiosalicylic acid' compound \vith'an acid condensing-agent.

-- 2. The process of producing coloring matter of the-thioindigo" group by treating acetylene bisthiosalicylic acid with chlorsulfonic acid.

In testimony whereof I have hereunto setmy hand in the presence of twoi'subscribing Witnesses.

. Witnesses:

J ALEo. LLOYD,

' R. SIos'BEa.

EDUARiD MUN H] 

